Calculator.



No. 745,167. PATENTED NOV. 24, 1903.

E. C. DUNCAN. CALCULATOR.

APPLICATION FILED SEPT. 5. 1902.

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PATENTED NOV. 24, 1903.

E. G. DUNCAN.

CALCULATOR.

APPLICATION FILED SEPT. 5, 1902.

2 SHEETS-SHEET 2.

N0 MODEL.

AN mw UNITED STATES Patented November 24, 1908.

PATENT UFFIQE.

CALCULATOR.

' SPECIFICATION forming part of Letters Patent No. 745,167, dated November 24%, 1 903'.

Application filed September 5, 1902. Serial No. 122,215. (No modeli) To 09% whom iv may concern:

Be it known that I, EMILY C. DUNCAN, a citizen of the United States, residing at Jennings, in the parish of Calcasieu and State of Louisiana, have invented a new and useful Calculator, of which the following is a specification.

The present invention relates to calculators; and the primary object thereof is to provide an exceedingly simple and readily-un derstood structure with which computations ordinarily requiring considerable time and care may be accurately and quickly made.

Another object is to provide a device of the above character in which parts may be readily substituted, so that computations of different kinds may be made.

The preferred form of construction is illustrated in the accompanying drawings and described in the following specification. It will of course be understood that modifications in the illustrated structure may be made.

In the drawings, Figure 1 is a perspective View of the calculator. Fig. 2 is a vertical sectional view through the same. Fig. 3 is a horizontal sectional view. Fig. t is a plan view of a portion of the table of calculations employed. Fig. 5 is a detail perspective view showing a different table of calculations and scales coacting therewith.

Similar numerals of reference indicate corresponding parts in all the figures of the drawlngs.

In carrying out the invention, as shown, a frame is employed comprising a base made up of cross-arms 10, from one of which rises a vertical standard 11, carrying at its upper end a horizontally-disposed arm 12, that is arranged over the base. In this frame is rotatably mounted an upright cylinder 13, having at its upper and lower ends gudgeons 14,

. respectively journaled in the arm 12 and the base. The upper gudgeon extends through the arm 12 and is provided with a suitable handle-knob 15. The cylinder carries on its outer face a table of calculations 16, preferably two different sets, said sets being arranged-in columns 17, that are located side by side. For example, in Figs. 1 and a the table illustrated isdesigned for computing in terest, and each set of the calculations is arranged in alternate columns.

Secured to the free end of the arm 12 is a depending finder-bar comprising a stationary section 18 and a movable section 19. The section 18 is suitably attached to the arm 12 by means of screws, as 20, and it is provided with a longitudinally-disposed opening 21, extending from the upper end of the cylinder 13 to a point contiguous to its lower end. This section terminates short of the base and is provided on its outer face and on opposite sides of the opening 21 with overhanging flanges22,formingguideways. In theseguideways is slidably mounted the section 19,which is thus movable longitudinally of the cylinder, said latter section being provided with a sight opening 23, which alines with the opening 21 of the stationary section. The sight-opening is of sufficient width to permit the exposure of two columns of the table of calculations, as will be clearly seen in Fig. 1, so that one column of each set can be seen. The movable section 19 is provided on opposite sides of the sightopening with finderscales, each of said scales coacting with the adjacent column, as will be explained more fully hereinafter. In the embodiment shown in Fig. 1 one of the flanges 22 of the stationary section is also provided with a series of numbers, shown as 6, 7, and 8, with which the scales of the sliding section also coact, these numbers constituting a rate-scale.

An indicator-dish 2 1 is secured to the base arms 10 and surrounds the lower end of the cylinder. This dish is provided on its upper face with an indicator-scale, (shown at 25,) which scale is arranged entirely around the cylinder, as illustrated. A pointer 26, attached to the cylinder, coacts with the indicator-scale 25 and is movable through the space between the lower end of the findersection 18 and the disk, thus permitting the cylinder to be completely revolved.

As already stated, the apparatus as shown 1 is intended for computing interest in 1 at six, seven, or eight per cent. The entire table of calculations has not been placed upon the same, as it can be readily computed by any mathematician; but a suflicient portion has been illustrated to explain the way in which the calculator is operated. Assuming, for instance, that it is desired to find the interest on one hundred dollars for one day at ICO siX per cent, the 100 mark on the sliding section 1b is placed at 6 on the flange 22. The cylinder is then revolved until the pointer 26 is at the numeral l on the indicator-scale 25. This will bring the several elements to the position shown in Fig. 1, whereupon the fraction 1/60 will be eX- posed beside the $100 mark, this being the result desired. In like manner the interest for one dollar will be exposed in the other columnnamely, 1/0000 of a dollar. It will be understood that the table of calculations on the cylinder will correspond to the different amounts shown on the slidingfindersection. Should it be desired to compute interest at seven per cent., it is only necessary to lower the slidingsection 19 until the $100 mark is opposite the numeral '7 on the fiange22. Thiswillbringthevariousamounts into alinementwith different rows of figures computed at seven per cent., and in a similar manner by lowering the $l00mark to 8 interest may be computed at that rate.

It will be apparent that this structure is very simple and can be cheaply manufactured. At the same time computations of an involved nature may be readily made thereon. It will of course be seen that different tables and scales may be employed, and as an instance of this in Fig. 5 is shown a different arrangement, the construction, however, remainingthe same. The apparatus shown in this figure is designed more espe cially for computing in hundreds. For in stance, if a commodity is sold at the rate of thirty-five cents ahundred pounds, the 100 mark on the sliding finder-section is arranged at 1, while the pointer26is turned to 35 on the indicator-scale 25. As a result it will be seen that the numeral 35 will appearat the 100 mark, while double that amount is shown at 200. In like manner the smaller scale is also brought into play and coacts with the adjacent column, thereby illustrating what the same commodity would be worth in less than hundred-pound lots. It is the intention to provide in connection with the frame a plurality of cylinders having different tables thereon and different scales which can be appliedand coact therewith.

From the foregoing it is thought that the construction, operation, and many advantages of the herein-described invention will be apparent to those skilled in the art without further description, and it will be understood that various changes in the size, shape, proportion, and minor details of construction may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-- 1. In a calculator, the combination with a supporting-frame, of an upright cylinder revolubly mounted on the frame and carrying a suitable table of calculations on its peripheral face, a stationary indicator-disk located at one end of the cylinder and having an indicator-scale on one of its side faces, a pointer carried by and projecting from the annular face of the cylinder,said pointer coacting with the indicator-scale, and an upright finder-bar arranged longitudinally of the cylinder and carrying a finder-scale that coacts with the table of calculations upon the cylinder.

2. In a calculator, the combination with a supporting-frame, of an upright cylinder revolubly mounted on the frame and carrying a suitable table of calculations on its peripheral face, a stationary indicator-disk located at the lower end of the cylinder and of greater diameter than the cylinder, said disk having an indicator-scale on its upper face, a pointer carried by the lower end of the cylinder and projecting over the upper face of the disk, coacting with the indicator-scale thereof, and an uprightfinder-bararrangedlongitudinally of the cylinder and having a sight-opening therethrough, said bar being provided alongside the opening with a finder-scale that coacts with the table of calculations upon the cylinder.

3. In a calculator, the combination with a frame, of a cylinder journaled in the frame and carryinga suitable table of calculations, an indicator located at one end of the frame and carrying an indicator-soale, a finder-bar carrying a finder-scale that coacts with the table of calculations upon the cylinder, said bar terminating short of the indicator and being secured to the opposite end of the frame, and a pointer attached to the cylinder and coacting with the indicator-scale, said pointer being movable in the space between the end of the finder-bar and the indicator.

4. In a calculator, the combination with a base, of an upright standard carried by the base and having an offset arm at its upper end, an upright cylinder journaled at its ends in the arm and the base and carrying a suitable table of calculations, a stationary indicator-disk secured to the base and surrounding the cylinder, said disk carrying an indicator-scale, a finder-bar carrying a finderscale that coacts with the table of calculations upon the cylinder, said bar being secured at its upper end to the offset arm and having its lower end terminating short of the indicator-disk, and a pointer attached to the cylinder and coacting with the indicator-scale, said pointer being movable in the space between the lower end of the finder-bar and the indicator-disk.

5. In a calculator, the combination with a movable table of calculations arranged in columns, of a finder arranged over the table, said finder comprising a stationary section located longitudinally of the columns, and a movable section adjustable longitudinally upon the stationary section and carrying a finder-scale that coacts with the table of calculations and is movable to diiferent places along the same column to change the relations between the finder-scale and the calculations.

6. In a calculator, the combination with a frame, of a cylinder journaled in the frame and carryinga table of calculations arranged in columns, a finder arranged over the cylinder, said finder comprising a stationary section located longitudinally of the columns, and a movable section adjustable longitudinally of the cylinder and carrying a finder scale that is located longitudinally of the columns,said scale being movable to different places along the same column to change the relations between the two.

7. In a calculator, the combination with a frame, of a cylinder journaled in the frame and carrying a table of calculations, a finderbar arranged over the cylinder, said bar comprising a stationary section attached to the frame and a sliding section movable longitudinally'of the cylinder, said sliding section having a sight-opening and being provided with a finder-scale that coacts with the table of calculations and is movable to different places along the same to change the relation between the two.

8. In a calculator, the combination with an upright frame, of an upright cylinder journaled in the frame and having a table of calculations thereon, an upright finder-bar arranged over the cylinder, said bar comprising a stationary section having an opening therethrough and provided with longitudinal guideways, and a movable section slidable in the guideways, said movable section having a sight-opening and being provided with a finder-scale arranged alongside said sightopening, which scale coacts with the table of calculations and is movable to different places along the same to change the relations between the two.

9. In a calculator, the combination with a frame, of a cylinder journaled in the frame and having different sets of calculations, said sets being arranged in columns that are located side by side, a finder-bar arranged over the cylinderandhavingasight-opening therethrough,said sight-opening being of sufficient width to expose a plurality of the columns, and separate finder-scales arranged on the finder-bar on opposite sides of the sight-opening, each of said scales coacting with one of the columns.

In testimony that I claim the foregoing as my own I have hereto affixed my signature in the presence of two witnesses.

EMILY G. DUNCAN.

Witnesses:

G. W. GARLIOK, JAS. A. SMITH. 

